package t20220303;

/**
 * @Author: DengJia
 * @Date: 2022/3/3 22:13
 * @Description:
 */

public class Immutable {
    public static void main(String[] args) {
        String s = "dengjia";
        System.out.println(s);
        String s1 = s.toUpperCase();
        System.out.println(s);
        System.out.println(s1);
    }
}
